1. Field of the Invention
This invention relates to a transfer feeder for hot-forging presses. This transfer feeder is a device for transferring a workpiece forged in a press to the next process, and transfer of the workpiece is accomplished by a pair of feed bars, i.e. front feed bar and back feed bar, repeating a series of clamping, lifting, advancing, lowering, releasing, and returning (or CLAMP, LIFT, ADVANCE, DOWN, UNCLAMP, and RETURN) as shown in FIG. 9.
2. Description of the Related Art
An example of a conventional transfer feeder is described in Japanese Patent Laid-Open No. 63-215330.
The clamping mechanism of this transfer feeder is constructed as shown in FIG. 10. 101 is a front feed bar and 102 is a back feed bar. A driving link 103 is connected to the front feed bar 101 and a driven link 104 is connected to the back feed bar 102. A motor-driven bolt-nut screw mechanism 105 is connected to the driving link 103, which is, in turn, connected to the driven link 104 through a transmission link 106. With this clamping mechanism, when the screw mechanism 105 is driven by the motor, the driving link 103 is directly set in motion and the driven link 104 is moved via the transmission link 106, and front and back feed bars 101 and 102 clamp the workpiece G.
FIG. 11 shows the advancing mechanism of the transfer feeder as shown in FIG. 10. Since the feed bars 101 and 102 are long, both consist of a central segment 101a and end segments 101b connected to both ends thereof.
With the conventional clamping mechanism as described, because the driven link 104 rocks via the transmission link 106, its rock path subtly differs in geometry from that of the driving link 103, and the clamp timing of the front feed bar 101 and back feed bar 102 are not perfectly synchronized and a clamping failure may occur.
In addition, with the conventional advancing mechanism, when the central segment shown in FIG. 11 is removed, the end segments 101b at both sides hang down. To avoid this, it is necessary to install cylinders 107 inside the upright in order to support the end segments. This involves a complex structure inside the upright.
Moreover, with the conventional transfer feeder, both the heavy clamping mechanism and advancing mechanism are completely raised and lowered. This involves high power for movement and makes quick movement impossible.